Method of carbonizing and superheating gas.



A. BERGLOP.

METHOD OF GARBONIZING AND SUPERHEATING GAS. APPLICATION FILED NOV. 1,1910.

1,085,096. Patented Jan. 20, 19M

2 -SHEETSSHEET 2.

ALGOT BERGIJOF, or cnrcaeofrnnmois. 4

mn'rnon or cannonrzme' Ann SUPERHEATING GAS.

Specification of Letters Patent.

Patented Jan. 20, 1914.

Application filed November 1, 1910. Serial No. 590,238.

To all whom it may concern:

Be it known that I, ALcor BERGLOF, a sub-;

' ject of the King of Sweden, residing at Chicago, countyof Cook, andState of Illinois, have invented a new and useful Improvement in Methodsof Carbonizing and Superheating Gas, of which the following is a full,clear, and exact description, reference being bad to the accompanyingdraw: ings, which form a partof this specification.

The method forming the subject matter of this application has for itsmain object,

to carbonize, in the reduction of ore spent gas, containin carbon-dioxid(CO and water-vapor 0) and to produce, for use in the reduction of ores,a gas practically free from nitrogen, carbon-dioxid and oxygen 'and tosuperheat such gas to temperatures varying as required up to the highesttem-' perature possible, about 1600-17 00 C. The method may also beapplied to the manufacture of water gas, and the gas produced may alsobe used for other purposes than reduction of ores. I

It consists, generally speaking, in preheating a spent gas, containingcarbon-dioxid and water-vapor or superheated steam, passing said gasthrough a mass of incandescent coke or charcoal not mixed with anymaterial of foreign nature, such as, for example, iron ore, and inmaintaining, in the mass of incandescent coke or charcoal, a temperatureof not less than 10001100 (1., through heat produced in the coke orcharcoal itself by electric energy, that is, without the combustion ofany part of the fuel with air, without access of air, and, consequently,also without diluting the gas with nitrogen.

To produce in the coke or charcoalv itself the heat required todissociate the carbondio xid and the water-vapor, to raise thetemperature of the gas and to replace the heat lost in radiation, etc.,twp poles (or a plurality of pairs of poles) are placed in contact withthe coke or charcoal and connected to a transformerarranged so that twoor more different secondary voltages can be provided. Anelec'trigcurrent is then passed through the mass of coke or charcoal andthe temperature is raised or lowered as required by means of passingthrough currents of higher or lower voltage. hen an electric current isthus passed through a mass of coke or charcoal the'electricenergyis, -on

account of the higher resistance of the coke or charcoal, converted intoheat and the heat produced per time unit (and the temperature) iscontrolled at will by changing the voltage of the current passingthrough the coke or charcoal, as more or less current is thus passedthrough said material per time unit and consequently also more or lessheat produced pertime unit. Carbon-dioxid and water-vapor will, whenpassing through an incandescent body of carbonaceous matter at atemperature of at least 1000 C., dissociate and each take up an atomofcarbon and be converted into carbon-monoxid and hydrogen.

The principal advantages of this improved process are; that a gaspractically free from nitrogen (which is a dilutant), oxygen andcarbon-dioxid (which causes reoxidation) and, therefore, of the highestpossible efficiency as a reducing-agent, can be produced; that thetemperature of the gas leaving the producing apparatus can be varied andbrought up to about I600 C.; and that the incoming gas, being preheatedto a temperature approximating that at which dissociation occurs, willbe dissociated in the lower zone of the coke so that combustion willoccur in that zone. This latter is an important feature of the processfor the reason'that, if the incoming gas entered the furnace at acomparatively low temperature, it would have to pass through the lowerzone of coke and be therein elevated in temperature before the oxygenrequired for the combustion of the coke would be liberated. Consequentlythe ashes would form above the.lower zone of coke, which would renderthe process uneconomical and inefficient.

If coke or charcoal is used as fuel, the

gas produced will contain practically only ill) prefer to employ for thepurpose of practising the process hereinbefore described.

In the drawings: Figure l is a vertical sectional view of the apparatus;Fig. 2 is a section on the line 22 of Fig. 1; Fig. 3 is a verticalsectional view of part of a modified furnace.

The apparatus consists of a rectangular shell 50 of cast iron, two sidesof which are straight while the other two sides slope toward each other,at the lower part set in a waterpan 51. The shell 50 is lined with fireor silica brick 52 and in the two straight sides are set two pairs ofcast iron plates or poles 40 and 11 connected by leads 42 and 43 withtransformers 44c and 45. WVithin the poles 4:0 and 41 are water channels56 connected by pipes 57 with a source of water supply. The electriccurrent passes from each transformer to the corresponding pole of apair, thence through the adjacent mass of coke or charcoal to the otherpole of said pair and thence back to the transformer.

The transformers receive their current from any convenient source ofsupply and the temperature in the furnace is controlled and regulated,as hereinbefore described, by connecting the primary leads so as toproduce different secondary voltages. These poles must be made ofmaterial having less resistance or higher-conductivity than the materialto be heated in which, according to its higher resistance, the heat is-pro-' duced by the,current passing through. Castiron, wrought-iron,steel, copper and nickel, etc., are all equally good when the fuelconsists of peat, coal or wood. The top of the apparatus is covered witha shallow cast iron pan (50, filled with water, and made in one piecewith the lower funnel shaped part 01 of the coal hopper, consisting ofthe two parts 62 and 63, separated by a bottom (54 with bell 65 and awater sealed top 60. The twyer 07 is of rectangular form, covered with amushroom shaped top 68 'and onnected with preheating pipes 69 and aninlet pipe 74, through which the spent gas is forced into the apparatus.In the upper part of the apparatus is a flue 70, which,

through a valve 71, communicates with the preheating chambers 72 fromwhich leads the fine 73, through which the produced gas is carried intothe apparatus in which it is to be used.

In starting the operation, the apparatus is filled to the upper end ofthe upper poles 40 with coke and the electric current is turned on andheat, as previously described, produced in the coke. hen the mass ofcoke and the apparatus has been slowly heated up, the temperature in thecoke is regulated to about 1000-1100 (l, the apparatus filled with thefuel to be used and the spent gas allowed to enter the apparatus throughtwyers 67, when the production of gas is started and then proceedscontinuously.

The fuel is charged into hopper and by bell 65 remove soon as this isnearly empty. from where it is further continuously and automaticallyfed part 62 of the into the apparatus through funnel 61 as the fuel isgradually consumed and shrinks, and

the ashes that collect in the waterpan 51 are removed as desired.

The spent gas, or (if water gas is to be produced) the steam, is forcedunder pressure through inlet pipe 74, preheating pipes 69 and twyers 67into the apparatus and through the superheated mass of the incandescentcarbonaceous material. When passing through this heated mass ofincandescent into part 63 as carbonaceous material, the carbon dioxidand the water-vapor of the preheated spent gas, or the superheatedsteam, are converted into carbon-monoxid and hydrogen, as previouslydescribed, and the gas, by regulating the production of heat in thecoke, superheated to, any temperature desired. These gases are in theupper part of the apparatus mixed with the volatile matters (mainlyhydrogen and hydrocarbons) which are there driven off from the freshfuel fed into the appara tus, and then, through flue 70, valve 71,preheaters 72 and fiiie 73, led out of the apparatus and into theapparatus in which the gas isto be used.

The spent gas is, on its way to the apparatus, preheated inpreheating-pipes 69 by the excess heat carried by the outgoing gas, partof which heat is in preheaters 72 carried -through the walls ofpreheating pipes69 and absorbed by the cold spent gas passing throughthese pipes simultaneously. with the outgoing hot fresh gas passingoutside of' said fpipes through preheaters 72 on its way out rom theapparatus; and the spent gas should be preheated to as near 1000 C. aspossible.

The velocity by which the gas is driven through the'apparatus, and theproduction of heat in the fuel, are regulated in such a way that the gasis given time enough in which to carbonize and to absorb the heat,during its passage through the heated fuel, and a sufficient quantity ofheat is produced in the coke to provide for the amount of heat needed togive the gas the temperature described.

While I have illustrated two pairs of poles in the apparatushereinbefore described, a single pair of poles, 46, as shown in Fig. 3,may be substituted. If a-single pair of poles is employed, only a singletransformer is of course necessary. The employment of a plurality ofpairs of poles is, however, preferred for the following reasons: Toaccomplish a complete carbonization of H 0 and G0, a constanttemperature of at least 10'00 C. (l0001100 C.) is required in thedissociation and carbonization zone of the apparatus (that is, the partlocated between the lower poles 41), but the temperature in thepreheating zone of the apparatus (that is, the part located between theupper poles 40) should be varied according to the desired temperature ofthe outgoing fresh converted gas. If, for example, it is desired toimpart a temperature of 1500 C. to the outgoing gas, the temperature inthe superheating zone should be kept at more than 1500 C. To impart thistemperature to the outgoing gas in an apparatus in which only one pairof poles is used, the temperature would have to be kept at 1500 C. evenin the dissociation zone, which would mean an unnecessary waste ofelectric energy. If, on the other hand, a temperature, for example ofonly 500 C. for the outgoing gas is desired the temperature in thesuperheating zone must be kept at a much lower point, in order to cooloff the gas which would leave the dissociation zone at about 1000 C.This would naturally be impossible if only one pair of poles were used.It would then be impossible to accomplish the cooling down of the gas inthe apparatus itself and the waste of electric energy would beconsiderable.

While in the claims I have specified passing the gas to be convertedthrough coke and coal, I, of course, do not intend to ex clude theemployment of other equivalent carbonaceous materials such as charcoalin place of coke and wood or peat in place of coal.

Having now fully described my invention, what I claim and desire toprotect by Letters Patent is 1. The method of carbonizing andsuperheating gas consisting of preheating said gas, passing an electriccurrent through a body of coke to maintain it incandescent at thedesired temperature and simi' ltaneously therewith passing saidpreheated gas through said coke while substantially preventing access ofair. Y

2. The method of carbonizing and superheating gas consisting in passingan electric current through a body of coke to maintain it incandescentat the desired ten'iperature, establishing a current of gas through saidcoke and leading the outgoing gas in proximity to the incoming gas toelevate the tempcrature of the latter.

3. The method of carbonizing and superlieating gas consisting inpreheating said gas, passing it successively through heated coke andcoal, passing an electric current through the body of coke to maintainit in- ('andcscent at the desired temperature, and feeding the coke andcoal (as the latter is carbon monoxid from converted into coke andfinally consumed) in a direction opposite to the flow of gastherethrough.

4. The method of carbonizing and superheating gas consisting inpreheating the gas, establishing a plurality of electric circuitsrespectively through contiguous masses of coke, independently regulatingsaid circuits to maintain said masses incandescent at differenttemperatures, and passing the preheated gas to be treated successivelythrough the coke mass of lower temperature and the coke mass of highertemperature.

5. The method of carbonizing and superheating gas-consisting inpreheating the gas, establishing a plurality of electric circuitsrespectively through contiguous masses of coke, independently regulatingsaid circuits to maintain said masses incandescent at dif ferenttemperatures, passing the gas to be treated successively through thecoke mass of lower temperature, the coke mass of higher temperature anda contiguous mass of heatedfresh fuel contiguous to the coke mass ofhigher temperature.

6. The herein described continuous process of producing gas, whichconsists in creating and maintaining a zone of high temperature in abody of carbonaceous material contained in a producer by the action ofelectric currents between electrodes so disposed as to use thecarbonaceous material as a resistance medium, introducing into the massof carbonaceous material highly heated waste gases of combustion wherebythe carbondioxid of the hot waste gases of'combustion are disassociatedto form carbon-monoxid therefrom together with a fresh amount of carbon-1nonoxid from the carbonaceous matter.

7. The herein described continuous process of producing gas whichconsists in creating and maintaining zones of high temperature in a bodyof carbonaceous material contained in a producer by the action ofelectric currents between electrodes so disposed as to.

use the carbonaceous material as a resistance medium, regulating thetempta-at'ures of said zones, introducing into the mass of carbonaceousmaterial highly heated waste gases of combustion whereby the' carbon-.dioxid of the hot waste gases of combustion are disassociated to formcarbon-monoxid therefrom together with a fresh amountof the carbonaceousmatter.

In testimony of which invention, I have hereunto set my hand, atChicago, 111., on this 29th day-of October, 1910.

i lVit-nesses DAVID H. FLETCHER,

JENNIE L. FISKE.

